关键词: 水煤浆, 气流床, 氮, 迁移

Abstract:

Various axial and radial concentrations of HCN, NH₃, NO and N₂ were measured during the gasification of coal water slurry (CWS) in a laboratory opposed multi-burner gasifier.The results showed that the majority of nitrogen pollutants (HCN, NH₃ and NO) came from the release of volatile nitrogen of coal during the rapid heating process of devolatilization.The maximum concentrations of nitrogen pollutants were produced at the nozzle plane and decreased away from the plane; moreover, the ordering in the aft-region was N₂>HCN>NH₃>NO.Increase of O₂/C ratio tended to favor the formation of N₂.Flow field distribution led to uniform radial concentrations at the exit and low concentrations near the side-wall in other axial positions.A proper amount of water in CWS tended to favor the formation of HCN and NH₃.However, the introduction of excessive steam played a role in restraining the release of volatile nitrogen and reducing the concentrations of HCN, NH₃ and NO.

Key words: 水煤浆, 气流床, 氮, 迁移